Renamed shift boundary condition enum to ShiftBC

lisainstrument/dynamic_delay_dask.py

lisainstrument/dynamic_delay_dsp.py

lisainstrument/dynamic_delay_numpy.py

lisainstrument/fixed_shift_dask.py

lisainstrument/fixed_shift_dsp.py

lisainstrument/fixed_shift_numpy.py

tests/test_dynamic_delay_dask.py

tests/test_dynamic_delay_dsp.py

tests/test_fixed_shift_dask.py

tests/test_fixed_shift_numpy.py